Automatic Door Locks

When a Front Door Lock Switch is activated in the "LOCK" or "UNLOCK" position, all of the doors lock or unlock in unison. Each lock can also be operated manually from the locking knob. In addition, with the Ignition Switch in "RUN," all Power Door Locks are automatically locked when the gear selector is moved from the "PARK" or "NEUTRAL" position or when the vehicle reaches a certain speed. The locks are operated by reversible motors that receive voltage from two relays in the Automatic Door Lock Relay. These relays operate to turn the motors on by applying voltage to one side of the Door Lock Motors and a ground to the opposite Door Lock Motor terminals.

When either Front Door Lock Switch is moved to the "LOCK" position, battery voltage is applied through the 195 CKT to the lock relay coil of the Automatic Door Lock Relay. The Automatic Door Lock Relay is energized, closing the door lock contacts and applying battery voltage to the Door Lock Motors via CKT 440 through the 295 CKT. Ground is applied to the opposite motor terminal through the normally closed unlock relay contacts within the Automatic Door Lock Relay. The Door Lock Motors then lock their respective doors.

When either Front Door Lock Switch is moved to the "UNLOCK" position, battery voltage is applied through the 194 CKT to the unlock relay coil of the Automatic Door Lock Relay assembly. The door unlock relay is energized, closing the door unlock contacts and applying battery voltage to the Door Lock Motors via CKT 440 through the 294 CKT. Ground is applied to the opposite motor terminal through the normally closed lock relay contacts within the Automatic Door Lock Relay. The Door Lock Motors then unlock their respective doors.

The Automatic Door Lock feature is controlled by the Multi-function Alarm Module. In vehicles equipped with an automatic transaxle, with the Ignition Switch in "RUN" and the gear selector moved from the "PARK" or "NEUTRAL" positions, the ground signal that is applied to the Multi-function Alarm Module from the Instrument Cluster via CKT 434 is removed. The Multi-function Alarm Module then momentarily applies battery voltage to the Automatic Door Lock Relay via CKT 195. All doors lock as described above. If the Multi-function Alarm Module receives a vehicle speed signal without having seen a ground signal on CKT 434, it momentarily applies battery voltage on CKT 195 to lock the vehicle doors. The module will lock the doors once per ignition cycle. The Multi-Function Alarm Module receives a vehicle speed signal from the Engine Control Module (ECM). If the Multi-function Alarm module receives a speed signal indicating that the vehicle is travelling faster than 8 mph and has not received a ground signal on CKT 434, it will momentarily apply battery voltage on CKT 195 at the Automatic Door Lock Relay to lock the doors. If the front doors are open, they will lock upon closing.